Savannah GuthrieTo Take Ann Curry's ChairTOMORROW

6/28/2012 4:40 PM PDT

Savannah Guthrie to Take Ann Curry's Chair TOMORROW

EXCLUSIVE

Ann Curry's chair isn't even cold yet ... but "Today" producers have already lined up a new ass to fill it for tomorrow's show ... and it belongs to Savannah Guthrie -- the woman who will replace Curry.

NBC sources tell us, Savannah will be anchoring with Matt Lauer Friday ... and it's "likely" they will formally announce the big switch during the show.

We're told the reason it's likely is because Matt is on vacation all next week for the holiday -- and the network wants to announce his new co-host while he's still around ... to show a united front.

TMZ broke the story ... Ann would be getting the chop after Matt made it clear he didn't want to work with her anymore. The declining ratings at "Today" didn't help.

After Ann's emotional exit announcement on Thursday's show, sources say she was in no mood to talk ... and kept quiet by herself in the studio until it was time to leave.

During exit negotiations, Ann had previously demanded the remaining $20 million of her co-hosting contract -- but NBC didn't want to pay her that kinda cash. It's unclear what kind of payout Ann will get, but our sources say NBC offered $10 mil.